1. Field of the Invention
The present invention relates generally to railroad brake monitoring systems, and more specifically to a monitoring and diagnostic system for a pneumatic only brakes on a rail car.
2. Description of the Related Art
Portable single car testers are known. These are used for cars that were not connected to a train. They put the brake valve and the brake system on the car through various tests by manipulating the valves and making various measurements at various points including the brake pipe pressure and brakes cylinder pressure. Typical examples are shown in U.S. Pat. Nos. 5,808,909, 6,094,997 and 6,269,682. An interface for connection to an electronically controlled pneumatic (ECP) brake system is described in the U.S. Pat. No. 5,808,909 patent.
Electric pneumatic brake systems are either stand alone electronic valves which are connected by wire or radio to the locomotive and receives braking signals electrically to control the brakes by controlling the air to and from the brake cylinder. The ECP system may also include an overlay or a pilot adaptor wherein a standard pneumatic valve is manipulated by the solenoids to perform its normal function while the brake pipe is still charged. Typical adaptor systems are shown by U.S. Pat. Nos. 5,390,988 and 5,676,431
U.S. Pat. No. 2,993,199 is a train inspection apparatus which determines whether a light or a full brake has been applied or whether the brakes have been released. This is an electrical polling system for a wired train. U.S. Pat. No. 2,993,199 and U.S. Pat. No. 5,390,988 monitor the brake cylinder pressure which is reported to the head end for the locomotive engineer. U.S. Pat. No. 5,676,431 includes a transducer for brake pipe, brake cylinder, and auxiliary reservoir and uses information to initiate braking electric pneumatically as well as addressing stuck brakes.
U.S. Pat. No. 5,862,048 is a microprocessor electric-pneumatic locomotive brake control and train monitoring system. This is an electric pneumatic brake system on the car with sensors whose valves are transmitted back to the head end processor in the locomotive. The braking diagnostic functions include stuck brake identification, release while the train is in motion, collective gradual release of train brakes, out of tolerance brake cylinder pressures, accelerated direct release brakes, the source of emergencies, wheel off detection, wheel identification by number and location, status of every train vehicle, box detection, and sliding flat wheels. This information and sensors are part of the EPC brake control system.
U.S. Pat. No. 6,175,784 is a remotely operated rail car status monitor and control system. The hand brake status and release monitor determines and reports the status of the hand brake and an operator releases the hand brake. The monitor also includes a perality of sensors which includes a slide wheel sensor and train handling sensor. The train handling sensor identifies impact. The car monitoring device responds to a wakeup signal from a hand held data terminal.
U.S. Pat. No. 6,837,550 is a brake system diagnostic using a hand-held radio device. The car brake system includes a radio based feed valve which includes a sensor to measure different pressures in the brake system. The hand-held device retrieves brake system data and information from the radio based feed valve and interprets the retrieved data and information. Maintenance is performed based on the interpretation of the data and information.